admin: default to port 12535, keep 23646 as a best-effort compat listener (#11816)

* admin: default to port 12535, keep 23646 as a best-effort compat listener

The default admin HTTP port 23646 derives a worker gRPC port of 33646
(port + GrpcPortOffset), inside the Linux default ephemeral range
(32768+). One of our own startup dials can claim 33646 before the admin
binds it, killing startup. This is the same failure #10209 fixed for
the test port allocator, still reachable via the mini default (#10838)
and via standalone `weed admin` defaults.

Move the default admin port to 12535 (gRPC 22535) everywhere, keeping
the http+10000 convention so worker -admin derivation, the Rust worker
and host:http.grpc addressing keep working:

- weed admin -port, weed mini -admin.port
- weed worker -admin, the plugin worker fallback, Rust worker and
  weed-lance-worker defaults
- help text, README, helm values, docker compose, tests

So old workers, bookmarks and scripts keep working, admin also serves
the same handler and the worker gRPC server on the previous default
(-port.legacy / -admin.port.legacy, default 23646, 0 disables). The
legacy gRPC port binds best-effort: it lives in the ephemeral range, so
a failed bind only warns instead of reintroducing the startup failure.
weed mini reserves it early like the primary port and keeps it out of
its own port relocation. grpc.Server tracks every listener handed to
Serve, so the compat listener stops with the primary.

Also warn when an explicitly configured admin port puts the derived
gRPC port at or above the ephemeral floor, the other fix suggested in
the issue.

Supersedes the pinned-grpc approach in #11814: pinning -admin.port.grpc
off the +10000 convention breaks external workers that derive the admin
gRPC port from the HTTP address. ClickHouse/ClickHouse#115512 pins
-admin.port on their side; this makes that pin unnecessary.

Fixes #10838

* admin: let services win the legacy ports, close compat listener on failure

Review findings on the compat listeners:

- Do not put the legacy ports in mini's reservedPorts: an explicit
  -s3.port=23646 or -master.port.grpc=33646 must be honored, not rejected
  or stolen by the early reservation. Mini now checks the finalized port
  set and skips only the conflicting compat listener, so HTTP and gRPC
  compat degrade independently and the service keeps its port.
- Also skip the legacy HTTP listener when a mini service owns the port:
  a wildcard-bound service can still leave loopback bindable, which would
  let the compat listener shadow it for loopback clients.
- Close legacyServer's raw listener in the deferred cleanup: Serve may
  not have registered it yet when startAdminServer returns early.
- Helm: add admin.legacyPort (default 23646) and expose the legacy
  http/grpc ports through the admin Service, container ports and
  NetworkPolicy so older workers resolved via the Service keep working.

* helm: only pass -port.legacy when it differs from the binary default

ct install deploys the released image with the new chart, and 4.48 does
not know -port.legacy, so the admin pod crash-loops. Omitting the flag at
the default value is behavior-identical on new binaries (their default
is also 23646) and keeps older releases installable; legacyPort: 0 or a
custom port still renders the flag.

docker/admin_integration/Makefile

@@ -26,7 +26,7 @@ build-and-restart: build ## Build with latest changes and restart services
 	@echo "2️⃣ Recreating workers to reconnect..."
 	@docker-compose -f $(COMPOSE_FILE) up -d worker1 worker2 worker3
 	@echo "✅ All services recreated with latest changes!"
-	@echo "🌐 Admin UI: http://localhost:23646/"
+	@echo "🌐 Admin UI: http://localhost:12535/"
 	@echo "💡 Workers will reconnect to the new admin server"
 
 restart-workers: ## Restart all workers to reconnect to admin server
@@ -64,7 +64,7 @@ start: ## Start the complete SeaweedFS cluster with admin and workers
 	@echo "✅ Cluster started!"
 	@echo ""
 	@echo "📊 Access points:"
-	@echo "  • Admin UI:      http://localhost:23646/"
+	@echo "  • Admin UI:      http://localhost:12535/"
 	@echo "  • Master UI:     http://localhost:9333/"
 	@echo "  • Filer:         http://localhost:8888/"
 	@echo ""
@@ -107,7 +107,7 @@ start-staged: ## Start services in proper order with delays
 	@echo "✅ All services started!"
 	@echo ""
 	@echo "📊 Access points:"
-	@echo "  • Admin UI:      http://localhost:23646/"
+	@echo "  • Admin UI:      http://localhost:12535/"
 	@echo "  • Master UI:     http://localhost:9333/"
 	@echo "  • Filer:         http://localhost:8888/"
 	@echo ""
@@ -136,7 +136,7 @@ status: ## Check the status of all services
 	@echo "Master:"
 	@curl -s http://localhost:9333/cluster/status | jq '.IsLeader' 2>/dev/null || echo "  ❌ Master not ready"
 	@echo "Admin:"
-	@curl -s http://localhost:23646/ | grep -q "Admin" && echo "  ✅ Admin ready" || echo "  ❌ Admin not ready"
+	@curl -s http://localhost:12535/ | grep -q "Admin" && echo "  ✅ Admin ready" || echo "  ❌ Admin not ready"
 
 logs: ## Show logs from all services
 	@echo "📜 Following logs from all services..."
@@ -157,7 +157,7 @@ master-logs: ## Show logs from master server
 
 admin-ui: ## Open admin UI in browser (macOS)
 	@echo "🌐 Opening admin UI in browser..."
-	@open http://localhost:23646/ || echo "💡 Manually open: http://localhost:23646/"
+	@open http://localhost:12535/ || echo "💡 Manually open: http://localhost:12535/"
 
 test: ## Run integration test to verify task assignment and completion
 	@echo "🧪 Running Admin-Worker Integration Test"
@@ -166,11 +166,11 @@ test: ## Run integration test to verify task assignment and completion
 	@echo "1️⃣ Checking cluster health..."
 	@sleep 5
 	@curl -s http://localhost:9333/cluster/status | jq '.IsLeader' > /dev/null && echo "✅ Master healthy" || echo "❌ Master not ready"
-	@curl -s http://localhost:23646/ | grep -q "Admin" && echo "✅ Admin healthy" || echo "❌ Admin not ready"
+	@curl -s http://localhost:12535/ | grep -q "Admin" && echo "✅ Admin healthy" || echo "❌ Admin not ready"
 	@echo ""
 	@echo "2️⃣ Checking worker registration..."
 	@sleep 10
-	@echo "💡 Check admin UI for connected workers: http://localhost:23646/"
+	@echo "💡 Check admin UI for connected workers: http://localhost:12535/"
 	@echo ""
 	@echo "3️⃣ Generating load to trigger EC tasks..."
 	@echo "📝 Creating test files to fill volumes..."
@@ -193,13 +193,13 @@ test: ## Run integration test to verify task assignment and completion
 	@echo "   • EC shards being distributed"
 	@echo ""
 	@echo "✅ Integration test setup complete!"
-	@echo "📊 Monitor progress at: http://localhost:23646/"
+	@echo "📊 Monitor progress at: http://localhost:12535/"
 
 quick-test: ## Quick verification that core services are running
 	@echo "⚡ Quick Health Check"
 	@echo "===================="
 	@echo "Master:  $$(curl -s http://localhost:9333/cluster/status | jq -r '.IsLeader // "not ready"')"
-	@echo "Admin:   $$(curl -s http://localhost:23646/ | grep -q "Admin" && echo "ready" || echo "not ready")"
+	@echo "Admin:   $$(curl -s http://localhost:12535/ | grep -q "Admin" && echo "ready" || echo "not ready")"
 	@echo "Workers: $$(docker-compose -f $(COMPOSE_FILE) ps worker1 worker2 worker3 | grep -c Up) running"
 
 validate: ## Validate integration test configuration
@@ -223,7 +223,7 @@ demo: start ## Start cluster and run demonstration
 	@echo "  • Load generator (creates files continuously)"
 	@echo ""
 	@echo "📊 Watch the process:"
-	@echo "  1. Visit: http://localhost:23646/"
+	@echo "  1. Visit: http://localhost:12535/"
 	@echo "  2. Observe workers connecting"
 	@echo "  3. Watch tasks being created and assigned"
 	@echo "  4. See tasks progress from pending → completed"
@@ -244,13 +244,13 @@ vacuum-test: ## Create test data with garbage and verify vacuum detection
 	@echo ""
 	@echo "1️⃣ Checking cluster health..."
 	@curl -s http://localhost:9333/cluster/status | jq '.IsLeader' > /dev/null && echo "✅ Master ready" || (echo "❌ Master not ready. Run 'make start' first." && exit 1)
-	@curl -s http://localhost:23646/ | grep -q "Admin" && echo "✅ Admin ready" || (echo "❌ Admin not ready. Run 'make start' first." && exit 1)
+	@curl -s http://localhost:12535/ | grep -q "Admin" && echo "✅ Admin ready" || (echo "❌ Admin not ready. Run 'make start' first." && exit 1)
 	@echo ""
 	@echo "2️⃣ Creating test data with garbage..."
 	@docker-compose -f $(COMPOSE_FILE) exec vacuum-tester go run create_vacuum_test_data.go -files=25 -delete=0.5 -size=200
 	@echo ""
 	@echo "3️⃣ Configuration Instructions:"
-	@echo "   Visit: http://localhost:23646/maintenance/config/vacuum"
+	@echo "   Visit: http://localhost:12535/maintenance/config/vacuum"
 	@echo "   Set for testing:"
 	@echo "     • Enable Vacuum Tasks: ✅ Checked"
 	@echo "     • Garbage Threshold: 0.20 (20%)"
@@ -258,7 +258,7 @@ vacuum-test: ## Create test data with garbage and verify vacuum detection
 	@echo "     • Min Volume Age: [0] [Minutes]"
 	@echo "     • Max Concurrent: 2"
 	@echo ""
-	@echo "4️⃣ Monitor vacuum tasks at: http://localhost:23646/maintenance"
+	@echo "4️⃣ Monitor vacuum tasks at: http://localhost:12535/maintenance"
 	@echo ""
 	@echo "💡 Use 'make vacuum-status' to check volume garbage ratios"
 
@@ -335,8 +335,8 @@ vacuum-help: ## Show vacuum testing help and examples
 	@echo "  make vacuum-demo           # Full guided demonstration"
 	@echo ""
 	@echo "Configuration:"
-	@echo "  Visit: http://localhost:23646/maintenance/config/vacuum"
-	@echo "  Monitor: http://localhost:23646/maintenance"
+	@echo "  Visit: http://localhost:12535/maintenance/config/vacuum"
+	@echo "  Monitor: http://localhost:12535/maintenance"
 	@echo ""
 	@echo "Custom Parameters:"
 	@echo "  make vacuum-data FILES=50 DELETE=0.8 SIZE=200"